well, lets say we have a rubber bar. which have three dimensions , length, thickness and width. and it you start pulling it from one side, one of it's dimension will be changed. similarly everything has time as a dimension . the value of that dimension is changing constantly in respect to a reference time. so, when you'll grow older an year later, your length , thickness and width , your dimensional value of time changes.
so when you travel through time, and go back to your 2 year old self, u can still exist because both got different dimensional values. and about the frame question... when you land on that time, you become a part of the that entire frame. so parallel world er bapar to mone hoy na ashtese...